1. Field of the Invention
The present invention relates to a droplet jet apparatus, and in particular, it relates to a compact droplet jet head having multiple high-density rows of nozzles and ejection chambers, and a droplet jet apparatus including the same.
2. Description of the Related Art
As recent electrostatic inkjet printers are increasing in the number of nozzles and rows of the inkjet head for high-speed printing and multicolor printing of high-resolution images, the number of nozzles per row and ejection chambers increase, thus increasing the length of the nozzle rows. The nozzle rows generally eject different colors of ink (e.g., red, green, blue, etc.) row by row.
Known droplet jet heads and droplet jet apparatuses mount device-control ICs directly on the surface of a substrate having ink channels and thermoelectric transducers, and has a flexible printed circuit (FPC) for supplying an input signal for driving the device-control ICs on the substrate (e.g., refer to Patent Document 1: Japanese Unexamined Patent Application Publication No. 2002-210969, FIGS. 1 and 2).
However, in the known droplet jet heads and droplet jet apparatuses (e.g., Patent Document 1), the device-control IC constitutes part of the nozzle surface, which requires a layer for protecting the surface of the device-control IC from ink, posing the problem of complicating the structure and manufacturing process.
Also, because the device-control IC is exposed, it is susceptible to outside air and vibrations, resulting in low durability.
Furthermore, the device-control IC is closer to print paper than the nozzles. This results in a long spread distance of ink droplets, so that the ink droplets cannot reach predetermined positions, making it difficult to achieve high-definition printing.
Since the ink channel and the FPC are disposed in opposite sides with the IC therebetween, the droplet jet head becomes large when the number of nozzle rows is increased.